Boons are ally friendly buffs with limited duration (aka buffs). There are 9 boons in total: Aegis, Protection, Regeneration, Fury, Might, Vigor, Swiftness, Retaliation, and Stability. The duration of the boons stack but not their effectiveness (exception is Might and Stability is completely unstackable). For example, if you put 10 seconds of regeneration on an ally and they already have 5 seconds of regeneration remaining, they will now have a total of 15 seconds of regeneration.[1]